How do you go about rebuilding a starter?

Hey guys,

Not a week and a bit ago I finally got the bike all up to snuff and running great - clean carbs, adjust valve clearances, floats wet set, sync done, new plugs, dyna coils, brakes lines and pads... The whole shabang!

Went for a couple of long rides - probably threw 1500 km on the bike and no problems! Until now...

The starter motor was getting slower... and slower... and slower... and now it's dead unless I tap it lightly with something hard. I think it's time for a rebuild, but I've never done this before. Looking through the search I found lots of people talking about doing it, but I'm not sure where to start after taking everything apart.

What should I clean, what should I look for, lube, keep try, adjust? Any advice?

Thanks,
Mike

 

It comes apart.
Clean the "Three areas"

1. Planetary end.
2. Motor
3. Electric end.

Buy a few Bottles of Isopropyl Alcohol.
A "Trigger-Pump" Sprayer.

After you get it on the bench ...
Scribe lines on BOTH ends to aid in re-assembly!!!

Two long screws hold BOTH indexed ends to the main body.

Remove the gear end and COMPLETELY clean and re-lube that end.
You'll need to spread one Circlip to get the Planet Main Shaft out.
Keep track of washers and spacers.
Look on the ends of the shaft and inside the housing for thin Thrust Washers that like to stay stuck where they are.

Keep everything in order as you disassemble the Planet end.
Two small Planet Gears on opposed shafts.
The Ring Gear and Main Shaft.
Every Spacer and Thrust Washer.

Clean the "Whole-works" of the "Business-end." All of it so nice and clean a Marine Drill Instructor would have the Company check-out yours as good example.

Check for washers and thrust washers hiding on shafts and bearing ports.

Clean the Electric end; too.

Pull the Case away from the Motor -- slowly.
There's LITTLE slack in the wire connecting the Brushes to the External Power Post.
Slip the Brushes off the Commutator.
Look for a Thrust washer - inside the Case - surrounding the port for the case bearing bushing.

With the starter exploded. Clean.
Use straight Isopropyl Alcohol loaded into a sprayer that has the Stream or Spray option.

Withdraw the Armature.
Spray everything until its completely clean and what you are spraying ON and IN is as clean as what is dripping OFF!

Shoot the Commutator, Brushes, Brush Housing, Electrical Lead and the inside of the Electric end Case.
Clean.

Shoot WD-40 on the CLEAN windings and magnets.
Grease the whole-works as you reassemble the Starter.
Using Top Quality Synthetic Waterproof Grease:
Everything and every surface on the Planet - Business End - gets lubed as it's reassembled.
Shafts, shaft bushing ID's, washers, spacers, gears, pivots, bushings, etc.
Grease everything. Either liberally -- for function, or smeared-on for both rotational forces on it ... or, to hold it from slipping as you reinsert bearing shafts into bushed port on the case.

Spin the Planet Shaft after its re-clipped in and grease the rotating Planet Gears -- "On the Fly" ... as they rotate around the inside of the Ring Gear.

Lightly smear washers and spacers on the Electric End ... but, don't allow the grease to contaminate electric connections and Commutator.

Get a dab of grease into the port on the Electric end; and smear the end of the shaft which fits there.

Now, the fun and games of getting the Brushes lifted onto the Commutator and everything lined-up and back together begin.

It's like a Chinese Puzzle.

Only ... "Made in Japan" !

 

Starters have 4 major components: Armature-coils or magnets-brushes-and a drive. Disconnect the battery, remove the starter, take it apart and clean with a non-flammable cleaner.

Brushes: will be in a brush holder, 2 negative brushes soldered to the brush holder, 2 positive brushes on a lead that goes to a battery terminal and coils if the starter has them. There are wear lines on the brushes, if the brush is worn down close to or past the line, replace.

Coils/magnets: called a field case. Coils are insulated wire wrapped around metal "shoes", if there is a break in the wire or the coil is shorted to the case, they need to be replaced. If magnets are used in place of coils: check for cracks or broken magnets. If magnets are damaged: get another starter.
Magnets are often damaged by someone tapping on the outside case, so if you tap on a starter, tap on the end.

Armature: Check the bars on the commutator for loose, bent, pitted or burnt bars, check if bars are shorted to the armature shaft and for excessive wear on shaft ends. If armature shows this, replace or get another starter. If all is ok, clean up commutator with a light sand paper by hand.

Drive: check for damaged gear teeth or burrs if you have the splined drive. Repair with a file. If you have a bendix style: check for excessive play on the shaft and gear slipping( spins easily). Replace if needed.
Planetary gear, replace if signs of wear are present.

Other: bearings,bushings,brush springs. Replace.

 

Awesome - just what I was looking for! Fingers crossed... I have a project for tomorrow after work!

Thanks Rick and Orange-n-Black!

 

One more thing, if you have a planetary gear and drive on a separate shaft, there's a small ball/bearing that goes in between the armature and the planetary shaft. Don't forget to put it back with a dab of grease or the shaft will slide back-n-forth.